Nitro-substituted heterocyclic nitrogen compounds as bird management chemicals



United States Patent This invention relates to the control of birds. In one of its aspects, this invention relates to a method for clearin an area of birds. In another of its aspects, this invention relate to bird management or bird anti-flying compositions.

The control of birds is one of the major problems confronting farmers and city managers at this time. For instance, the loss of grain and seed by bird consumption represents considerable financial losses to farmers each year. Cities frequently spend many thousands of dollars a year in an attempt to drive away birds and thus prevent the defacing of buildings and the like. Furthermore, there have been several airplane crashes attributed to flocks of birds circling in the landing pattern and near the ends of airport or airfield runways.

Various means have been employed to scare or otherwise drive birds away from certain localities. For example, scarecrows have been used for many years by farmers in grain fields or other areas, although this method has actually met with little success. More modern versions of the scarecrow, such as artificial owls and the like, have also met with little success. Certain types of noisemakers such as sirens and the like have likewise been used. Still more recently, chemical repellents have been developed which, to some extent, alleviate the problem.

Ths invention relates to novel bird control compositions and to a method for clearing an area of birds by subjecting birds within said area to the action of certain heterocyclic nitrogen-containing compounds.

Accordingly, an object of this invention is to provide novel bird management or anti-flying compositions.

Another object of this invention is to provide an effective method for clearing an area of birds.

A further object of this invention is to provide novel compositions and a method for protecting property from birds, especially materials normally consumed as food by birds.

Other aspects, objects and the several advantages of this invention will be apparent from a study of this disclosure and the appended claims.

According to the present invention, it has been found that the activity of birds can be controlled by subjecting birds to the action of an effective amount of a heterocyclic nitrogen-containing compound having a structural formula selected from 2 wherein (l) X is selected from the group consisting of N: -L OJILHZO and N= (2) n is an integer selected from the group consisting of 0, 1 and 2, (3) Y is selected from the group consisting of R,

and nitro radicals, and at least one Y is selected from the group consisting of and nitro, (4) R is selected from the group consisting of hydrogen,

methyl and ethyl radicals, and (5) When Y is nitro, X is -N=.

The compounds of Formula I above are preferred, and it is preferred that only one of said Y groups be either or nitro. It is also preferred that said R groups on the group be hydrogen. Furthermore, it is preferred that not more than one of said Y groups be alkyl, As to position, it is preferred that said or nitro group be located in the 4-position and if one of said Y groups is alkyl, it is preferred that said alkyl group be located in the 3-position.

Representative and specific heterocyclic nitrogen-containing compounds of the above described general structural formulas that can be employed according to the practice of the present invention include:

4-aminopyridine 4-aminopyridine-N-oxide 4-amino-3-methylpyridine 4-amino-3-methylpyridine-N-oxide 4- (N-methylamino) pyridine-N-oxide 4- (N,N- dimethylamino pyridine-N-oxide 3-aminopyridine 3-aminopyridine-N-oxide Z-aminopyridine 2,6-dian1inopyridine 4-amino-2-methylpyridine-N-oxide 4-amino-2,6-dimethylpyridine 3-amino-2,4,6-trimethy1pyridine 4-amino-2-methylquinoline 4-arnino-2-methylquinoline-N-oxide dihydrate 3-amino-2-ethylpyridine-N-oxide 4-aminoquinoline 4-aminoquinoline-N-oxide 4-amino-2,3-dimethylquinoline-N-oxide monohydrate 4-amino-2,6-dimethylquinoline 2,8-diaminoquinoline 3-aminoisoquinoline S-amino-1-methylisoquinoline-N-oxide 4-amino-2-methyl-5-ethylnvridine 3 4-amino-2,3,5,6-tetramethyipyridine-N-oxide 4-(N,N-diethylamino) -2,3,5,6-tetraethylpyridine-N-oxide 4-amino-2,3,5,6,7,8-hexaethylquinoline-N-oxide dihydrate S-nitropyridine 4-nitropyridine 4-nitro-3 -methylpyridine 3-nitro-2-methylpyridine 4-nitro-2,S-dimethylpyridine 4-nitro-2-methyl5-ethylpyridine 4-nitro-2,3,6-trimethylpyridine 3-nitro-2,4,6-trimethylpyridine 4-nitro-2,3,5,6-tetraethylpyridine 3,5-dinitropyridine 3-nitroquinoline 4-nitro-2,8-dimethylquinoline S-nitroisoquinoline 4-nitro-2,6-diethylquinoline 4-nitro-3 -methylisoquinoline 4-nitro-2,3,5,6,7,8-hexaethylquinoline Many of the compounds of the invention can be purchased from commercial sources, but not all are available. Synthesis of these compounds can be effected by conventional techniques. Some typical methods follow. For example, one can proceed in the synthesis of these compounds by first forming the N-oxide. Generally, one mole of pyridine is reacted with one mole excess) of hydrogen peroxide which is charged as 30 percent aqueous H 0 Acetic acid is used as the diluent and is present at a 4/1 molar ratio of acetic acid to pyridine. The acetic acid also serves as the oxygen carrier, forming peracetic acid in situ. The conditions for the reaction are approximately 85 C. for hours.

After the N-oxide such as pyridine-N-oxide is formed, it is usually most convenient to nitrate, as for example to form 4-nitropyridine-N-oxide. This can be carried out by conventional nitration procedures using a typical molar ratio of pyridine-N-oxide/HNO /H SO of 1/ 3.0-3.5/ 3.5-7.0. Nitration of the N-oxide is necessary to obtain the ratio group in the 4-position.

After the nitrated N-oxide such as 4-nitropyridine-N- oxide is formed, one can proceed by several methods to form the anti-flying or bird management chemicals of this invention. If one desires to convert 4-nitropyridine-oxide to 4-nitropyridine, reaction with PCl will remove the N- oxide group. Similarly, reduction of 4-nitropyridine-N- oxide under rather severe conditions will simultaneously reduce the nitro group to an amino group and remove the oxide group. For example, treatment of 4-nitropyridine-N-oxide with hydrogen at about 500 p.s.i. and 100 C. in water or alcohol and in the presence of l percent by weight based on the N-oxide of 10 percent palladium on charcoal catalyst will yield 4-aminopyridine. However, if the same catalyst is used at milder conditions, say 60 p.s.i. and 30-40 C., 4-aminopyridine-N-oxide is obtained. Synthesis of 4-dimethylarninopyridine-N-oxide can be effected by treating 4-nitropyridine-N-oxide with acetyl chloride to form 4-chloropyridine-N-oxide. This compound can then be reacted with dimethylamine to form 4-dimethylaminopyridine-N-oxide. Similar reactions can be employed to form the other compounds which contain, for example, such substituent groups as alkyl radicals.

The compounds of the present invention can be applied for their intended purpose as a concentrate, or in com bination with a carrier or other inert materials. Solvent or adjuvant carriers employed should be substantially inert with respect to the active anti-flying compound. Some examples of specific carrier materials that can be employed are acetone, deodorized kerosene, naphthas, isoparaffinic hydrocarbon fractions boiling in the range of about 260 to about 800 F. (Soltrol) and the like. If desired, the anti-flying compounds of this invention can be applied as aqueous emulsions by employing a suitable emulsifying agent. It is also within the scope of this invention to employ mixtures of the heterocyclic nitrogencontaining compounds and to employ mixtures of one or more of these compounds with other known bird control agents.

It has been found that the various compounds disclosed above are effective anti-flying agents. Birds that have eaten even a very small amount of these anti-flying or bird management agents are unable to fly for some time, and during this period of time (inability to fly) the birds undergo convulsions, emit warning or distress cries to other birds, and the like. It is not known definitely by what mechanism these warning cries or convulsive actions serve to drive other brids away from affected birds but, as shown by the specific examples hereinbelow, the compounds of the invention are extremely effective for clearing birds from an area after at least one of the birds has been subjected to the action of one of the compounds of the invention.

Ingestion of a sufficient amount of at least one of the compounds of the invention defined above by one or more birds produces symptoms such as tremors, loss of flight, fluttering, paralysis, and warning and distress cries. The result is that other birds, upon seeing birds having convulsions or suffering from paralysis, and hearing the distress cries emitted by affected birds, even entire flocks of birds, will leave an area and stay away from the area for long periods of time.

When employing the bird management or anti-flying compounds of this invention to clear birds from an area, one or more of the birds in the areas to be cleared must ingest an effective amount of at least one of the compounds in order to achieve the best results. The active anti-flying compound can be ingested by the birds by feeding the birds treated food or by injecting a small amount of at least one of the compounds into at least one of the birds bodies by suitable means. The compounds of the invention can be conveniently given to birds by treating a food normally eaten by the birds and thereafter placing the treated food or bait in the area from which it is desired to clear the birds. For example, grains such as sorghum, corn kernels, chopped corn, chicken feed, kaffir corn, and the like, can be employed as well as such materials as potatoes, bread and the like. If a grain is used, a convenient method for treating the grain comprises impregnating the grain with a solution of oneof the agents and a volatile solvent and thereafter evaporating off the volatile solvent. Acetone is a convenient solvent for use in such a method of operation. If, however, bread is used as a bait, inverted emulsions in mayonnaise or other oily material are suitable methods for applying the anti-flying compounds to the bread.

Whatever method is employed for treating the bird food, the treated food will generally contain from 0.01 to about 10 percent by weight of the anti-flying compound. The lower percentages will, of course, be used when the more active agents are to be employed, while the higher percentages will be used with the less effective agents. Larger or smaller amounts, however, can be employed, when desired, although larger amounts are generally uneconomical.

In actual operation, birds can be effectively cleared from an area, building, or other locality, with a very minor amount of one of the above-described compounds. It can be seen that by employing small amounts of treated grain, for example, one need not treat the entire area such as would be required if a true repellent material was employed. By operating in this manner, buildings, airport runways, grain fields, and the like can be cleared of birds and maintained clear of birds for prolonged periods of time. This is particularly advantageous in grain fields since the farmers can place small amounts of treated grain in the fields shortly before the grain ripens, thus clearing the birds from the fields before they have a chance to eat the crop. After the crop has been harvested, the use of treated bait or bird food can be discontinued. In many instances, it is desirable to first lure the birds into an area with a bait or untreated grain, and then place treated bird food in the area for the birds to consume with the result that the affected birds Warn and scare other birds away from that particular area.

The following specific examples are intended to illusmeasure of efiectiveness when comparing the agent to another compound producing these effects.

The results of the tests are expressed below as Fable I.

Table I trate the advantages of the bird management or anti-flying 5 AMI OPYRIDI E-N-OXI 13 compounds of this invention, but it is not mtended to lrrmt N N D the invention to the embodiments shown herein. As dis- Com ound LD Observed Effects cussed above, it has only been specified how much of the p mgJkgfLX anti-flying compound to deposit on treated bait. In the following examples, it will be shown that various agents 4-amin0pyridine-N-0Xide 50 X 75 Convulsions, cant fiy, are required in diiferent dosages to obtain the desired dlstress canssymptoms. The amount of active ingredient ingested by 4-amjno-2-pico1jne-N- xide X 1,000 u shakes, a bird needed to obtain the desired results will vary l g Nlervousi Cant 011ml -0x1 e. egs. depending upon the compound employed and the species 4-((1I\ ]',Nim ehy1ami1 0)pyri- 300 X 500 Flopping Symptoms, of birds treated. Since one wishing to clear an area of 15 4-amiuo-2,5-d1meth l ldme- 500 X 1,000 Droo birds by the method of this invention has no control over N-oxide. y W the amount of treated food that a bird will eat, it is im- *fifig X 1Y000 N0 effect at 1059 used' possible to specify exactly what dose will be applied to s-e mho-2,'4,s-trimeth 1 ri- X 1,000 Droopy. birds under actual conditions. However, one method which can be used for selecting between species of birds is the use of different sized grain. For example, sparrows AMINO'SUBSTITUTED HETEROCYCLIC COMPOUNDS cannot eat Whole kernel corn whereas pigeons can eat such food very readily. Thus, if one wishes to clear *ammopyrldme X 40 l z g pigeons from a building or other area where only small 3-arninopyriginem 3 328500 Nergpus.

1 2-a1ninopyri inc. 1 00 0. populations of sparrows exist, whole corn can be used 29 zmiammopyrid X 1v000 Do exclusively. 2,4,6-triaminopyrid 500 X 1,000 DroOpy.

The following examples illustrate the effectiveness of 4ammo'a'methylpynd 100 X 150 g g f and the compounds of the present invention but are not g-amino-g-miithybplyrfdined 300 g ggg gonvulsiolnsk i -ami110- ,6-(irne ypyri ine r0opy,s a y. f however unduly the Scope of the Famine-2,5-dimethylpyridinc 100 X 500 Shaky, some cries. mVCIlilOn. 30 3-an1i11o-2,4,6-trimetl1y1pyri- 500 X 1,000 Droopy.

me. EXAMPLE I 4-amln0quiualdine 100 X 300 Do. A series of runs was carried out in which a variety of amino-substituted heterocyclic compounds were tested as COMPARATIVE RUNS bird management chemicals.

In these runs, the chemicals to be tested were given Pyridine X 1, 000 No effect. orally, by means of a syringe and stomach tube, to chicks 'g i gfgg gg 3g; 10 to 15 days old. The eflect on the chick in each case was noted, and sufficient runs were carried out to determine the L1) for each chemical. L1) is the dose EXAMPLE 11 required in mg. of chemical per kg. of bird weight to 40 In a further series of runs, starlings were treated with kill percent of the chicks. Although LD is not a some of the chemicals tested in Example I. In these runs, measure of the value of a chemical as :a bird control agent, a measured dose of the chemical Water was forced into all of the bird management or control agents which we the stomach by means of a tuberculin syringe. The results have found have high toxicity to birds. Thus, when a of these tests are expressed as Table II. In the table, the chemical is noted to produce convulsions, cause distress 45 numbers are for intensity of reaction; ()no reaction, cries, prevent flying, etc., the LD providesa good 1-slight, 2noticeable, 3-conspicuous and 4violent.

Table II Dosage Loss of Flutter- Weak- Loss of Minutes Chemical trig/kg. Tremors Flight lng ness Aware- Voice To ness Reaction 4-amin0pyridine 19 2 3 1 3 3 1 1 :23 D0 20 1 3 2 1 2 2 130 35 3 3 4 3 4 1 :53 39 2 3 4 2 4 1 :23 35 1 2 1 1 1 2 :25 40 1 0 0 1 1 1 :37 00 4 4 3 3 4 4 :14 04 3 4 4 3 4 4 =22 3 3 4 3 4 3 =11 3 3 3 3 4 2 :12 0 0 0 0 1 0 :07 0 0 0 0 1 0 :07 1 0 0 1 2 0 :03 135 1 0 0 1 2 1 :05 220 4 3 3 1 4 4 :5 225 3 4 4 2 4 4 =03 230 2 0 0 1 1 1 =9 245 3 4 4 2 4 4 :05 425 4 3 3 3 4 1 :2 530 4 3 3 3 4 1 :3 137 3 3 4 2 4 4 :05 192 3 3 4 3 4 4 =10 233 3 3 3 2 4 3 =07 240 3 3 4 2 4 4 :08

7 EXAMPLE III A series of "runs was carried out in which a variety of nitro-substituted heterocyclic compounds were tested as bird management chemicals.

In these runs, the chemicals to be tested were given orally, by means of a syringe and stomach tube, to chicks 10 to 15 days old. The effect on the chick in each case was noted, and sufficient runs were carried out to determine the LD' for each chemical. LD is the dose required in mg. of chemical per kg. of bird weight to kill 50 percent of the chicks. Although LD= is not a measure of the value of a chemical as a bird control agent, all of the bird management or control agents which we have found have high toxicity to birds. Thus, when a chemical is noted to produce convulsions, cause distress cries, prevent flying, etc., the LD provides a good measure of effectiveness when comparing the agent to another compound producing these effects.

The results of these test are expressed below as Table III.

8 EXAMPLE vr To determine possible secondary poisoning effects of 4-aminopyridine, a group of sparrows were fed 16 grams of kafiir corn containing 0.5% by weight of this com- 5 pound. This amount killed all of the sparrows. A cat was fed 19 of these dead sparrows over a four-day period, and no apparent ettects on the cat were noted.

EXAMPLE VII Pans of corn chops, red sorghum and white sorghum which had been treated with an acetone solution of 4- aminopyridine were set out in a location heavily frequented by pigeons. The amount of solution used was such that the grain, after evaporation of the solvent, contained 1 percent by weight of the bird management agent.

The estimated pigeon population was 140-150 at the time the treated grain was set out. One day later, the number of pigeons in the area was 85 and after 3 more days, the number frequenting the area was down to 30. Many pigeons were observed during the three day period to "have convulsions and were unable to fly.

As will be evident to those skilled in the art many variations and modifications of this invention can be practiced in View of the foregoing disclosure. Such vmiations and modifications are believed to come within the spirit and scope of the invention.

We claim:

1. A method for reducing the number of birds in an area which comprises placing in said area a bird food treated with 0.01 to percent by weight, based on said food, of a hereterocyclic nitrogen-containing compound EXAMPLE IV having a structural formula selected from In a further series of runs, starlings were treated with Y Y some of the chemicals tested in Example ILL -In these O runs, a measured dose of the chemical in water was Y Y Y Y forced into the stomach by means of a tuberculin syringe. H H The results of these tests are expressed as Table IV. In the table, the numbers are for intensity of reaction; 0no reaction, 1-slight, 2noticeable, 3-conspiou0us and 4-violent. (I) Table IV Dosage Loss of Flutter- Weak- Loss of Distress Minutes Chemical rug/kg. Tremors Flight ing ness Aware- Cries to Reae- Survival ness tron t-nitropyridine 4 0 0 0 0 0 0 None Recovered. Do 5 0 0 0 0 0 0 None Do. 5 0 o 0 0 0 0 None Do. 5 1 0 1 2 1 3:00 Do. 5 1 0 1 2 0 3100 Do. 8 0 0 0 2 2 2 3:00 D0. 8 0 0 0 1 2 1 3:00 Do. 12 3 3 1 2 2 2 s=0o D0. 16 4 4 3 3 3 4 3:00 Do.

EXAMPLE V and A chick feeder containing 50 grams of untreated white Y Y sorghum and another chick feeder containing 50 grams of treated white sorghum were olfered to cowbirds in one C cage and pigeons 1n another cage on a free chorce basis. Y-C C CY The treated food was prepared by contacting the grain d0 1, with a 10% by weight solution of 4-aminopyridine-N- oxide in acetone and thereafter evaporating oil the solvent. Y Y 'In one test, involving pigeons and grain containing 1 (In percent by weight of the agent, two out of three pigeons wherein were dead within four hours after placing the treated grain in the feeder. All three pigeons exhibited con- (1) Y is selected from the group consisting of R and vulsions, tremors and the like. Similar results were obnitro radicals, at least one Y being nitro, and tained on pigeons when grain containing 0.5% by weight 2) R is selected from the group consisting of hydro- 4-aminopyridine-N-oxide except that only one pigeon gen, methyl and ethyl radicals.

out of four was dead after four hours.

In a test on cowbirds using 0.5 of the agent on the grain, one cowbird out of four was dead after 4 hours. All of the cowbirds experienced convulsions and emitted ones.

2. A method according to claim 1 wherein the birds are attracted into the area to be cleaned with bait.

3. A method for preparing a bird management composition which comprises impregnating a bird food with 0.01 to 10 weight percent, based on said food, of a heterocyclic nitrogen-containing compound having a structural formula selected from (1) Y is selected from the group consisting of R and nitro radicals, at least one Y being nitro, and

(2) R is selected from the group consisting of hydrogen, methyl and ethyl radicals.

4. A bird management composition comprising a bird food containing from 0.01 to percent by weight, based on said food, of a heterocycli'c nitrogen-containing compound having a structural formula selected from said said

said

said

said

References Cited in the file of this patent FOREIGN PATENTS 1,013,113 Germany Aug. 1, 1957 

1. A METHOD OF REDUCING THE NUMBER OF BIRDS IN AN AREA WHICH COMPRISES PLACING IN SAID ARA A BIRD FOOD TREATED WITH 0.01 TO 10 PERCENT BY WEIGHT, BASED ON SAID FOOD, OF A HERETEROCYCLIC NITROGEN-CONTAINING COMPOUND HAVING A STRUCTURAL FORMULA SELECTED FROM 